For the purpose of clarity, only “turning machines” are subsequently described.
Turning machines for the purposes of the present patent application are also interpreted to also be all turning-machine derivatives. Thus, e.g., combined turning and milling machines and combined turning and broaching machines, thus any machine in which a workpiece is driven in rotation by a spindle, and tool units like, e.g. turning tools, milling tools, broaching tools or grinding tools are movable along the rotation axis of the workpiece and also transversal thereto and that are configured to process the workpiece.
Turning machines are typically used for fabricating workpieces that are typically rotation symmetrical or at least partially rotation symmetrical through clamping the workpiece, e.g., in a chuck, and driving it in rotation through a head stock, and causing a material removal at the rotating workpiece through engaging tools, like, e.g., stationary tools (turning) or rotating tools (side mills, end mills or disc shaped broaching tools) or tools that are moved tangentially in a straight line (broaching tools).
The tool units are thus movable in a Z-direction, the rotation direction of the workpiece and are additionally movable in at least one of the transversal directions (X- and Y-direction).
In turning machines, the turning tools are typically disposed in a larger quantity on a pivotable revolving disc, and the tool revolving disc is at least movable in X-direction and in Z-direction.
Typically, two revolvers of this type are disposed on opposite sides of a rotation axis.
For different machine concepts, the rotation axis of the workpiece can be arranged in a horizontal or vertical direction.
Additionally also, cold rolling is known in order to press teethings, threads, annular grooves, knurling, oil grooves or other contours onto the workpiece circumference through a cold forming process through pressing accordingly contoured rollers or bars against the circumference of the rotating workpiece.
Since significant contact forces against the workpiece are required for this purpose, such cold rolling is typically performed in a separate cold rolling machine when larger numbers of workpieces shall be processed.
It is furthermore also known to use a cold rolling unit in a turning machine by inserting the much smaller cold rolling unit, which typically has two forming rollers, in a tool receiver of a tool revolver of the turning machine.
On the one hand, the press forces applicable to the workpiece are certainly much smaller as a function of the maximum load bearing capability of the tool receiver and of the tool revolver including its guides.
This certainly limits the size, in particular the depth of the embossings on the workpiece, which are producible as a function of the work piece material.
On the other hand, this also causes relatively quick wear of the forming rollers, which are very small due to their mounting location, so that they are only usable to process small batches, but no large batches.
Another disadvantage of this solution is that the dimensional precision of the profiles that are producible at the workpiece is not optimal due to the many disengageable connections, thus supports and similar, that are provided between the forming rollers and the bed of the machine.
Between these two extremes, thus a separate cold rolling machine on one hand, and a cold rolling unit with very limited utility in a tool receiver of a turning machine revolver on the other hand, however, there is a wide gap for solutions for the problems, which exist in the majority of practical applications.